Fuel-injection apparatus for internal-combustion engines and like purposes



G. AMI-:RY INJECTION APPARATUS FOR INTERNAL March 27, 1945.

' FUEL 2,372,169 coMBUsTIoN ENGINES AND LIKE Punross Filed Apr-i1 19,194s mm-Inl..

35 Gsokcf Ane-kr Kt N Patented Mar. 27, 1945' l'UNITED STATES 2MT1-:rrrOFFICE FUEL-.INJECTION APPARATUS FOR INTER- ENGINES 'AND LIKENAL-CODIBUSTION rUarosEs George Amery, Harborne, Birmingham 17, England,assignor to Amery Holdings Limited, Oldbury,A Birmingham, England, aBritish 4com- Pall! Application April 19, 1943, Serial No. 483,652 InGreat Britain February'l'l, 1942 s claims. (c1. 137-144) Thisinventicn'comprises improvements in or relating to fuel-injectionapparatus for internalcombustion engines.

According to'the present invention a fuelcontroll valve comprises avalve-body, an inlet thereto, a plunger therein having aduct extendingthrough it from one end open to the inlet toward a seating at the otherend, an obturatingmember movable toward the plunger to bear on the`seating and thereby close the duct against the flow of fuel through theduct, a piston face on the obturating-member exposed to inletfuelpressure to urge it open and control means independent of thefuel-pressure, controlled by the valve, to close the obturating-memberagainstv said pressure, whereby seating andunseatingof theobturating-member is efiectedto close andv open the valve, the plungerand seating thereon being freel to move with the obturating-member for ashort distance in the closing direction after the valve is closed. v

The invention includes an iniector or distributor having a fuel-controlvalve as above set.'

forth wherein an expansion chamber is provided between the` plunge'randan annular shoulder or abutment engaging therewith, whichchamber is incommunication with the fuel-nozzle of the iniector and on the relativemovementy which'l occurs between the shoulder and plunger when.

the plunger and obturating-member move together after the valve isclosed serves to relieve fuel-pressure at'the nozzle for the purpose ofensuring a rapid cessation of Iinjection when the Y valve is closed. v

' The fuel-control valve may employed to -oontrol the admission of fuelto a needlevalve seating for the injector or distributor and the lclosing `means for the needle-valve or plunger or obturating means, asthe case may be, may be assisted, if desired, by spring action, althoughin certain forms according to the invention the employment of springsmaybe obviated.

'Ihe preferred arrangement according tothis inventionleads to anexceptionally rapid fall of fuel-pressure when obturation occurs butnotbefore.

v Referring now to the accompanying drawing--V Figure 1 illustrates inlongitudinal section a fuel-injection devic'e for an internal-combustionengine, while rFigure 2 illustratesa lcross-section through the lineII-II in Figure 1.

Figure 3 illustrates in cross-section a modification. j

Figure 4 is a diagram of the essential parts of the valve asillustratedin Figure 3. The invention willnow be described, by way ofexample, as applied, more particularly to the arrangement described andillustrated with reference to Figures '4 and 5 of my United StatesPatent No. 2,053,311, granted September 8, 1936, wherein a number ofinjectors are operated from l a single fuel supply system. A pipeconnection with this system is made directly to each injector forinjection purposes and a branch from this pipe' connection is led by wayof a mechanically-actuated valve 'to each injector. Thismechanically-actuated valve controls the. operation of the injectorassociated therewith so that at the moment when injection is to commencethe valve cuts oil? the piston closingmeans from communication with thesupply system and places the chamber containing they pistonc1osing-meansin yconnection .with the atmosphere or with a drain pipe, while at themoment when injection is .to be cut on the valve places the pistonclosing-means in the injector in communication with the 'supply system.

The inlet pipe I I, -Figure l,.leads fuel from the fuel pressure systemto the injectorlIZ.' The Y, b ody I 3 of the injector is tubular and itsupper bore 22 in which a free plunger 23 is slidable, the' upperend ofthe bore 22 opening into thev recess I9. The plunger 23 is provided witha central duct 2l and the lower end of this plunger `is integral withV apiston 25 arranged in a cham-V ber 26. The lower end of the chamber 26is formed by the upper end Awall of a constriction 28 arranged betweenthis chamber and a charnber 29,`the lower wall of the chamber 26 beingf'med with an annular lprojection 30 concentric with this chamber. Theconstriction 28 has a central bore 3I in which a plunger 32 is slid-Aable, the upper 4end face of this plunger being adapted to seal or actas an obturating-member for the lower end of the duct 21 of the piston25 when these parts are in contact with each other.

A duct 33 extends between the lower end of ius. /v

.if desired.

' passes.

' nipple 65 of the body I3 of the injector.

the chamber 26 and the upper end of the chamber 29, the upper end ofthis duct opening from the face of the annular projection 30 into theformer chamber.

A bore 34 extends from the chamber 29 to the lower end of the injectorbody I3. The bore 34 is divided into two control-chambers 35 and 36 bythe member 31 which is fixed in position by means of' a grub screw 33. Aduct 39 of the member 31 interconnects the control-chambers 35 and 36,and this duct is connected by a duct 40 with a control-pipe 4I from themechanicallyactuated valve above described which acts as a distributor.The control-pipe 4I is formed with a conical end 42 which fits into thecorrespondingly shaped part of the duct 40. The end 42 of the pipe 4I ispressed into uid-tight'contact with the conical wall of the duct 40 bythe annular projection 43 on the end of a nut 44, the screw of whichengages with 45 of the nipple 46 formed on the body I3 of the injector,when the nut 44 is tightened up.

In the control-chamber 35 is disposed a control-piston 41 which actuatesthe plunger 32. It will be noted that the area of control-piston 41 issomewhat greater than that of plunger 23 to ensure that it can lift theplunger against fuelpressure in pipe II. mounted a piston 48 which isconnected to, or formed integrally with, the stem 49 of a needle valvevwhich seats in a, nozzle 52. The needle valve 49 need not, in theconstruction according to the present invention, be spring-closed, but aspring may be provided to assist in closing it,

'Ihe lower end 5I) ofthe injector body I3 is screw-threaded externallyand with this end an internally screw-threaded union I engages. Thisunion connects the nozzle 52 with the injector body I3.

VBetween the nozzle 52 and the lower end of the injector body I3 isarranged a jointing ring 53 formed with a central clearance hole 54through which the stem 49 of the needle valve The jointing ring 53 has aduct 55 formed in it which is connected at its lower end to a duct, notshown, leading to a chamber in the nozzle the internal screwthreadV Inthe chamber 36 is.

In Figure 1 the position of the parts corresponds to that in which theneedle valve is closed and consequently no fuel is being injected intothe cylinder of the internal-combustion engine with which the injectoris associated. The mechanically-operated valve or distributor has openedthe distributor control-pipe 4I to the pressure of the fuel supplysystem so that the pressure of the fuel oil in the ducts 4D and 39 andin the adjacent ends of the control-chambers 35 and 36 is that of thesupply pressure in the fuel system. Accordingly the piston `I8 holds thesurrounding a. shoulder on the needle valve, while y opens into acylindrical chamber 51 closed at itsouter end by a screwed plug 58.Another duct 5.9 connects the chamber 51 with the lower part of thechamber 26.

A duct 60 is formed in the body I3 of the injector I2 and thisductconnects the lower end of the chamber 36V (below the piston 48) with thechamber 29. The chamber 29, Figure 2, is connected by a'duct 6I to apipe 62 leading to the atmosphere or acting as a drain pipe andconnected to a. suitable'receptacle. The pipe 62 has a conical end 63which is forced into fluid-tight contact with a similarly formed end ofthe duct 6I on screwing up the nut 64 of which the screwthread engageswith an internal thread on4 the The plungers 23, 32 and the pistons 25,

tight manner in their correspondingly shaped respective bores orchambers, 25. 3|, 35 and 36 and packing grooves may be formed on theplungers or pistons if desired.

The operation of the injector above described is as follows:

needle lvalve closed and the piston 41 holds the plunger 32 against thelower end of the duct 21 in the piston 25 and has sealed this duct. -Thepressure of the fuel oil in the inlet pipe I I which acts on the upperend of the plunger 23 forms a fluid-tight joint between the lower end ofthis plunger and the upper face of the piston 25. Thelower face of the'piston 25 is held clear of the annular projection 30 so that pressure inthe nozzle chamber is relieved through the ducts and 56, chamber 51,duct 59, the part of the chamber 25 between the lower face of the piston25 and the upper face of the constriction 28, duct 33, chamber 29, duct6I and pipe 62. The pipe 62 leads to the atmosphere or to a drain pipe.The parts remain in the above position until the instant arrives forfuel injection to commence.

When this instant arrives the pressure of the fuel oil system is cut offfrom the control-pipe 4I and consequently the pressure of the oil in thecontrol-pipe 4I, duct l4I), duct 39 and the adjacent ends of thecontrol-chambers 35, 36 is relieved with the result that the pressure ofthe fuel supply system in pipe Il acting on the plunger 23 forces theplunger downwards and also the piston 25, plunger 32, and piston 41,until the lower face of the piston 25 rests on and makes a fluid-tightjoint with the annular projection 30 which prevents any further movementof the piston 25 andA also of the annular piston 23. 'I'he pressure ofthe fuel oil acting in the duct 24 on the upper end of the plunger 32forces the-plunger downwards still farther with the result that the fueloil may now pass from the duct 21 into the space enclosed within theannular projection 30 and from thence through the duct 59, chamber 51,ducts 56 and 55 to the nozzle chamber and the pressure of the fuel oilon the needle valve shoulder opens the valve so that fuel oil isinjected in a finely atomised condition into the combustion chamber ofthe cylinder of the internal-combustion engine associ- I 41 andY 48 areall of cylindrical form and slide in a fluidated with the injector. Thepiston 25 when in contact with the annular projection 30 seals the duct33 leading to the chamber 29 and to the pipe 52 which leads to theatmosphere or to a drain pipe.

When the instant arrives for injection to terminate, the distributorplaces the control-pipe 4I, duct 40, duct 39 and controlchambers 35 and36 in communication with the pressure fuel supply system so that thepressure in this system acts on the adjacent ends of the pistons 41 and4B. The pressure on the piston 48 closes the needle valve on its seatwhile the pressure of the fuel supply system is= still vacting thereon,and as the area'of the control-piston 41 is greater than the area of theplunger 23 plus that of the duct 24, the plunger 32 closes the lower endof the duct 21 and then forces the piston 25 upwards so that thelowerAface of the piston 25 is moved away from the annular projection 30 uponwhich it previously rested. When the piston 25 has been raised of theannular projection 36 the pressure in the nozzle chamber is relieved by.y beingiconnected to the atmosphere or drain pipe `by way ofthe duct55, ductf56, chamber 51, the

part of the chamber 26 beneath the lower face of the piston 25,duct 33,chamber 29,v duct 6I and pipe 62.

The above cycle of operations -is repeated so long as the injectionsystem ,.functions.

Instead Lof forming the various `bores and chamber in the body ftheinjector, they may be formed in one or a number of liners andassembled with the body. v.

The injector as above described while operating eiliciently Vis open tothe disadvantage that in the event of a particle of carbon lodging onthe needle valve seat during combustion' or compression strokes of theengine cylinder associated with the injector, and of the needle valvebeing.

thereby prevented from closing prolllerly,- gases under pressure couldblow fuel oil remaining in the injector ducts and passages into theatmosphere or into the drain pipe. In order to obviate the abovecontingency arising, the construction of the injector may be modified asillustrated diagrammatically in Figure 3.

In Figure 3 a plunger 23 has a central duct 2t and is slidably mountedfluid-tight in a bore 22 of the injector body I3. Beneath. the bore 22is arranged a guide member 1U which is xed in an enlarged vbore. 1I. Atits upper end the guide member has a chamber 1.2 which is of smallerdiameter than the bore 22 so that a shoulder 13 is formed upon which theplunger 23 rests when in its lowest position. The plunger 32 is slidablymounted fluid-tight in a bore 14 of the guide member 10, the obturatingplunger 32 being operated by a control-piston 41 slidable in a chamber35, The control-chamber 35 vis formed in a liner inseited in a bore 16ofthe body I3 of the injector and is interconnected by a duct 39 with achamber 36 also formed in the liner 15. In the chamber 36 there isslidably mounted a piston 48 which is formed on the stem 49 of theneedle valve of the injector. The duct 39 is connected by' a duct 40 toa nipple 46 onthe body I3 of the injector, the nipple being connected tothe distributor pipe. Duets 11 and 18 leadfrom the upper-end of thechamber and from the lower end of the chamber 36 to the atmosphere or toa drain pipe. The chamber 12 is connected by a duct 19 to the. needlevalve chamber in the nozzle. A screwed plug B0 serves as an adjustablestop to limit the outward or return movement of the plunger 23. Theremaining parts of the injector are similar to that described withreference to Figures 1 and 2.

By arranging the injector as just described a sulicient increaseofvolumetric capacity may be given (bythe increase of volume of expansionchamber 12 when the plunger 32 is lifted) to the ducts associated withthe nczzle valve chamber and located within the injector so as torelieve the pressure in the fuel oil ducts without discharging'the fueltothel atmosphere or to the drain pipe.

When injection commences the dfstributor cuts off the pressure fuel oilsystem from the distributor pipe connected to the injector by the nipple48 and relieves the pressure in the ducts 43 and 39 and in the ends ofthe control-chambers 35 and 36 connected by the duct-39. The pressure ofthe fuel oil supply acting on the plunger 23 forces this plungertogether With the obturating plunger 32 and the piston 41 downwardsuntil ated.

the plunger 22 rests on the shoulder 13. -l The pressure of the fuel oilacting in the 'duct 24 on the upper end of the plunger 32 forces thisplunger still farther downwards and at the same time breaks the sealbetween the upper end of this plunger and the lower end of the plunger22. 'The fuel oil may then freely pass by way of the chamber 12 and theduct 19 to the needle valve which it opens and so enters the cylinder ofthe engine associated therewith.

When injection terminates the distributor connects the adjacent ends ofthe control-chambers `35 and 36 through the ducts 39 and 46 and thenipple 4| to the pressure fuel supply system. The piston 48 is operatedand closes the needle valve. Moreover, the control-piston 41 rises andoperates the plunger 32 so that it seals the lower end of the duct 2lioi the plunger 23 and raises the plunger sufficiently to supplement thecapacity of the chamber 12 by that of the displacement of the plunger 23in the bore 22 and to relieve the pressure in this chamber and also inthe duct 19 andthe nozzle valve chamber.

When injection recommences,' the plunger 32 is pressed down by thepressure of the fuel oil supply acting on the plunger 23, and thepressure in the chamber 12 and duct 19 and nozzle chamber is increasedprior to the opening of the duct 24. This tends to reduce or preventpressure waves and fluctuations of pressure in the whole system. Withthis construction the needle valve will be efficiently sealed by plunger19 even if it does not seat properly at the nozzle 52 and `the fuel oilaround the needle valve seat when. the valve has been closed is notunder pressure owing to,the relief aiorded by expansion of chamber 12.

It is desirable when applying the presentinvention in practice toincludea valve so a1'- ranged that injection cannot talee place until asuitable pressure of injection is generated.

The valve which is constituted by the plunger 23 coacting with theplunger or obturatingmember 32 forms in itself a very useful valve iwhich may be used in other connections, for example a-s a valve for thedistributor itself, such for example as the distributor valve shown at9|' in Figure 5 of my United States Patents 2,291,- 939, granted August4, 1942, and 2,281,302, granted April 28, 1942. In Vthis case theplunger 32 of such a distributor valve may be cam-oper- The essentialparts of the valve, when iluid-pressure-operated, are illustratedseparately in diagrammatic form in Figure 4 and bear the same referencenumbers as in Figure 3. In this case A represents an inlet, B an outletto be controlled by the valve and C an inlet for pressure to control theopening and closing of the valve. l

The constructions of injectors hereinbefore described are not limited tosuch as have pistonclosing means for the fuel admission-valve which holdthe needle valve 49closed substantially solely by fiuid pressure asmovement of either or both of the. piston-opening and piston-closingmeans may be assisted by spring action.

' I claim: x

1. A fuel-control valve for fuel-injection apparatus ofinternal-combustion engines and like purposes comprising a valve-body,an inlet thereto, a plunger therein having a duct extending through itfrom one end open to the inlet toward a seating thereon at the otherend. an'obturating-member movable toward the plunger to bear Von theseating and thereby close the duct against cated and an inlet from anindependent supply of fluid under pressure to said chamber to close theobturating-membler against said pressure,

whereby seating and unseating of the obturat` ing-member is eiected toclose and open the valve, the plunger and seating thereon being free tomove with the obturating-member for a short distance in the closingdirection after the valve is closed.

2. A fuel-control valve for fuel-injection apparatus ofinternal-combustion` engines and like purposes comprising a valve-body,a plunger therein having a duct extending through it from a seatingthereon at oneend, an obturating-meinber movable toward the seating toobturate the duct, means to admit uid pressure to the end of the plungerand urge the plunger and obturatingmember in one direction, an abutmentin the path of the plunger to interrupt its movement while allowing themovement of the obturating-niember to continue under the said pressureand thus to open the valve, an outlet passage leading from theobturating member beyond the seating on the plunger, a secondpiston-face on the other.

end of the obturating member, a control-chamber in which said secondpiston-face is located and an inlet from an independent supply or iiuidunder pressure to said chamber to return the obturating-member to closethe valve and to thereafterv continue the movement of the obturatingmember and plunger together for a short distance so as to return theparts to their initial position.

3. A valve as claimed in claim i, wherein an expansion chamber isprovided between the plunger and an annular shoulder'or abutmentengaging therewith, which chamber is in com munication with the outletpassage and, on the relative movement which occurs between the shoulderand plunger when the plunger and obturating-member move together afterthe valve is closed, serves to relieve pressure in the outlet passage.

fi. A valve as claimed in claim i wherein the movement of the plungerwith the obtiiratingn asume member after the valve is closed is limitedby an adjustable stop for the purpose described.

5. A valve comprising in combination a valve l body having a cylindricalbore near one end thereof, an inlet at the end of the valve body to thecylindrical bore, a plunger slidable in the bore and pierced with alongitudinal passageway, a seating on the end of the plunger remote fromthe inlet, the plunger being at liberty to execute limited endwisesliding movement in the bore, a smaller bore in the valve body beyondthe plunger and coaxial therewith, an obturating member slidable in saidbore and capable of sealing the passageway through the plunger byabutting upon the seating, a chamber surrounding the junction of theobturating member and the plunger, an outlet passage from the saidchamber, an additional valve member movable to open and close the outletpassage and control means for closing the second valve and forsimultaneously closing the obturating member upon the seating andforcing back the plunger to relieve pressure in the outlet passagebetween the chamber and the additional valve member.

6. A valve comprising in combination a valve body having a cylindricalbore near one end thereof, an inlet at the end of the valve body to thecylindrical bore, a plunger slidable in the bore and pierced with alongitudinal passageway, a seating on the end of the plunger remote tromthe inlet, the plunger being at liberty to execute limited endwisesliding movement in the bore, a smaller bore in the valve body beyondthe plunger and coaxial therewith, an obturating member slidable in saidbore and capable of sealing the passageway through the plunger byabutting upon the seating, a chamber surrounding the vjunction of theobturating member and tne plunger, an outlet passage from the saidchamber, an additional valve member movable to open and close the outletpassage, a control chamber in the valve body, a control piston upon theobturating member open to said control chamber, a second control pistonupon the said additional valve member, also open to said control chamberand an inlet to the valve body for application ci fluid pressure to saidcontrol chamber to close the additional valve andto operate theobturating member to close it upon the seating of the plunger.

GEG'RGE

